1. Field of the Invention
This invention relates to new and useful improvements in vacuum apparatus for use in surgery and more particularly to vacuum apparatus having reduced output of noise and a reservoir sized to provide substantially instantaneous response when needed during surgery.
2. Brief Description of the Prior Art
Surgical aspirators presently available on the market were mostly adapted from vacuum extractors used by OB-GYN physicians for therapeutic abortions. These machines were slow to build up to maximum pressure, and generally had low volume flow rates at maximum vacuum. In order for vacuum to be available, the machines had to run continuously or be cut on and off, the surgeon having to wait several seconds for maximum vacuum to build up each time it is needed. Also, all of the early machines and most of the present-day machines are excessively noisy so that if the machine is being used for an hour or longer, the noise becomes an unpleasant factor.
Modern surgeons who use aspirators have a demand that the vacuum be continuously available for the entire surgical procedure. They want the machine to be able to deliver maximum vacuum as quickly as possible. The surgeon's cyclic need for maximum vacuum many times during the surgical procedure means that if there is a wait 5-10 second wait each time for the machine to reach maximum vacuum, the sum of all of the 5-10 second waiting periods can add up to a significant amount of time the patient is exposed to anesthesia.
Additionally, if the machine's flow rate at the maximum vacuum isn't high enough, the surgeon has to proceed with the surgery more slowly, again exposing the patient to longer periods of anesthesia.
The surgeon's need for the instant availability of maximum vacuum means the nurse or surgeon must manually cut the machine off and on, or the machine must run continuously, giving rise to noise pollution.
Most manufacturers of modern aspirators have tried to handle the surgeon's need for a high flow rate and rapid rise to maximum vacuum by placing two motors and two vacuum pumps into each machine and/or placing larger, more powerful motors and vacuum pumps in the aspirator.
A number of patents have dealt with the problems of noise abatement and reservoir size and utilization.
Guarniery U.S. Pat. No. 1,380,473 discloses a suction pump for player pianos having surrounding sound deadening material.
Vose U.S. Pat. No. 2,290,259 discloses a hair dryer with sound deadening material surrounding the fan motor.
Crago U.S. Pat. No. 4,264,282 discloses an air compressor pump having surrounding sound deadening material.
Wang et al. U.S. Pat. No. 4,395,258 discloses surgical vacuum apparatus with an accumulator and various control features.
Mayoral U.S. Pat. No. 4,676,779 discloses surgical vacuum apparatus with various control features.
Kayser U.S. Pat. No. 4,3I5,506 discloses surgical vacuum apparatus for aspirating fluids from body cavities.
The prior art in general, and the cited patents in particular, does not disclose an apparatus with the control features provided by this invention or the complete sound deadening provided by utilizing the vacuum chamber as a sound insulator.